[Objective] Exploring the impact of hydropower development on local climate is an important guarantee for preventing and mitigating the possible negative effects of hydropower development and realizing sustainable energy development and environmental protection. [Methods] Four typical hydropower stations, Longkaikou and Guanyinyan in the middle reaches of the Jinsha River and Xiluodu and Xiangjiaba in the lower reaches of the river, were selected. By applying the climatic propensity rate, the M-K trend test, and the wavelet analysis, this study quantitatively analyzed the monthly, seasonal and yearly changes of temperature and precipitation before and after the impoundment of water in the middle and lower reaches of the river, as well as the sudden changes in the development of hydropower and the cyclical characteristics. [Results] (1) After water storage, the hydropower station had an inhibitory effect on the highest temperature and an uplifting effect on the lowest temperature in the valley. In summer and autumn, the downstream hydropower station played a cooling role, and the average monthly temperature decreased significantly in February, June, July, September, October and November, while the midstream hydropower station did not have the temperature regulation effect, with only a slight decrease in average air temperature in July. (2) After water storage, precipitation in each season increased significantly, with an increase of 0.71~27.95 mm in April, August, and September. (3) Air temperature and precipitation were related to hydropower development, and the air temperature and precipitation of the mid-and downstream hydropower stations underwent abrupt changes at different times during the development and after the water storage. (4) Air temperature and precipitation showed similar characteristics in wavelet change period, and after water storage, local precipitation showed more significant periodicity and had a certain degree of stability. [Conclusion] At different time scales, hydropower development affected local temperature and precipitation varied across river reaches, and was constrained by multiple factors such as geographic location, the surrounding environment and water storage duration.